OCB mode transflective liquid crystal display device

Abstract

An exemplary liquid crystal display device ( 2 ) includes: a first substrate ( 21 ) and a second substrate ( 22 ); a liquid crystal layer ( 23 ) having liquid crystal molecules located between the first and second substrates, the liquid crystal molecules are intermingled with chiral dopant, and are in a twist π cell state before the liquid crystal display device is turned on; and a plurality of pixel regions. Each of the pixel regions defines a reflection region and a transmission region, whereby a thickness of the liquid crystal layer in the reflection region is less than a thickness of the liquid crystal layer in the transmission region.

1 . A liquid crystal display device, comprising:
 a first substrate and a second substrate;   a liquid crystal layer having liquid crystal molecules located between the first and second substrates, the liquid crystal molecules being intermingled with chiral dopant, and being in a twist π cell state before the liquid crystal display device is turned on; and   a plurality of pixel regions, each of the pixel regions defining a reflection region and a transmission region.   
   
   
       2 . The liquid crystal display device as claimed in  claim 1 , wherein when the liquid crystal display device is turned on, the liquid crystal molecules are converted from the twist π cell state into a bend alignment state so that the liquid crystal display device is able to operate in an optically compensated bend (OCB) mode. 
   
   
       3 . The liquid crystal display device as claimed in  claim 1 , wherein a ration d/p=0˜1, wherein d represents a thickness of the liquid crystal layer in the transmission regions, and p represents a pitch of the chiral dopant. 
   
   
       4 . The liquid crystal display device as claimed in  claim 1 , wherein a thickness of the liquid crystal layer in the reflection regions is less than a thickness of the liquid crystal layer in the transmission regions. 
   
   
       5 . The liquid crystal display device as claimed in  claim 1 , wherein a thickness of the liquid crystal layer in the reflection regions is equal to a thickness of the liquid crystal layer in the transmission regions. 
   
   
       6 . The liquid crystal display device as claimed in  claim 1 , further comprising a first alignment film disposed between the first substrate and the liquid crystal layer, and a second alignment film disposed between the second substrate and the liquid crystal layer, wherein each of the first and second alignment films is a homogeneous aligned alignment film, and the alignments of the first and second alignment films are parallel to each other, and a pre-tilt angle of the liquid crystal molecules adjacent to the first and second substrates is in the range of 0° to 15°. 
   
   
       7 . The liquid crystal display device as claimed in  claim 6 , wherein the liquid crystal molecules are positive uniaxial liquid crystal material. 
   
   
       8 . The liquid crystal display device as claimed in  claim 6 , further comprising a first polarizer disposed at an outer surface of the first substrate and a second polarizer disposed at an outer surface of the second substrate, wherein the first polarizer has an absorption axis perpendicular to an absorption axis of the second polarizer. 
   
   
       9 . The liquid crystal display device as claimed in  claim 8 , wherein the absorption axis of the first polarizer is parallel to a rubbing direction of the first alignment film. 
   
   
       10 . The liquid crystal display device as claimed in  claim 9 , further comprising a first retardation film disposed between the first polarizer and the first substrate, and a second retardation film disposed between the second polarizer and the second substrate. 
   
   
       11 . The liquid crystal display device as claimed in  claim 10 , wherein a slow axis of the first retardation film maintains an angle of 45° relative to the absorption axis of the first polarizer, and a slow axis of the second retardation film maintains an angle perpendicular to the slow axis of the first retardation film. 
   
   
       12 . The liquid crystal display device as claimed in  claim 11 , wherein the first and second retardation films are wide-band quarter-wave plates. 
   
   
       13 . The liquid crystal display device as claimed in  claim 11 , wherein the first and second retardation films are single compensation films. 
   
   
       14 . The liquid crystal display device as claimed in  claim 11 , wherein the first and second retardation films are A-plate compensation films. 
   
   
       15 . The liquid crystal display device as claimed in  claim 11 , wherein the first and second retardation films are discotic molecular films. 
   
   
       16 . The liquid crystal display device as claimed in  claim 10 , further comprising a third retardation film disposed between the first retardation film and the first polarizer, and a fourth retardation film disposed between the second retardation film and the second polarizer. 
   
   
       17 . The liquid crystal display device as claimed in  claim 16 , wherein the third and fourth retardation films are half-wave plates. 
   
   
       18 . The liquid crystal display device as claimed in  claim 17 , wherein an absorption axis of the first polarizer maintains an angle in the range from 10° to 20° relative to a slow axis of the third retardation film, and an absorption axis of the second polarizer maintains an angle in the range from 10° to 20° relative to a slow axis of the fourth retardation film. 
   
   
       19 . The liquid crystal display device as claimed in  claim 18 , wherein the slow axis of the third retardation film maintains an angle in the range from 55° to 65° relative to a slow axis of the first retardation film, and the slow axis of the fourth retardation film maintains an angle in the range from 55° to 65° relative to a slow axis of the second retardation film. 
   
   
       20 . A liquid crystal display comprising:
 a first substrate and a second substrate;   a liquid crystal layer having liquid crystal molecules located between the first and second substrates, the liquid crystal molecules being in a twist π cell state before the liquid crystal display device is turned on; and   a plurality of pixel regions, each of the pixel regions defining a reflection region and a transmission region; wherein   a height of said liquid crystal layer is variant in a staggered manner.